Convert //ios from scoped_ptr to std::unique_ptr.

ios/web/navigation/crw_session_entry_unittest.mm

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/web/navigation/crw_session_entry.h"
 
 #import <Foundation/Foundation.h>
 #include <stdint.h>
 
 #include <utility>
@@ skipping 21 matching lines @@
  public:
   static void expectEqualSessionEntries(CRWSessionEntry* entry1,
                                         CRWSessionEntry* entry2,
                                         ui::PageTransition transition);
 
  protected:
   void SetUp() override {
     GURL url("http://init.test");
     ui::PageTransition transition =
         ui::PAGE_TRANSITION_AUTO_BOOKMARK;
-    scoped_ptr<web::NavigationItemImpl> item(new web::NavigationItemImpl());
+    std::unique_ptr<web::NavigationItemImpl> item(
+        new web::NavigationItemImpl());
     item->SetURL(url);
     item->SetTransitionType(transition);
     item->SetTimestamp(base::Time::Now());
     item->SetPostData([@"Test data" dataUsingEncoding:NSUTF8StringEncoding]);
     sessionEntry_.reset(
         [[CRWSessionEntry alloc] initWithNavigationItem:std::move(item)]);
   }
   void TearDown() override { sessionEntry_.reset(); }
 
  protected:
@@ skipping 274 matching lines @@
 TEST_F(CRWSessionEntryTest, NonEmptyVirtualUrl) {
   web::NavigationItem* item = [sessionEntry_ navigationItem];
   item->SetVirtualURL(GURL("http://user.friendly"));
   EXPECT_EQ(GURL("http://user.friendly/"), item->GetVirtualURL());
   EXPECT_EQ(GURL("http://init.test/"), item->GetURL());
 }
 
 TEST_F(CRWSessionEntryTest, EmptyDescription) {
   EXPECT_GT([[sessionEntry_ description] length], 0U);
 }